Haleoelastomer and doped metal oxide compositions

ABSTRACT

A composition having a) a haloelastomer with halogenated monomers, polyorganosiloxane monomers, or both halogenated and polyorganosiloxane monomers, and b) a doped metal oxide, preferably antimony doped tin oxide, dispersed or contained therein, wherein the composition can be formed into films or outer layers of components useful in xerographic processes.

Attention is directed to copending application Attorney Docket NumberD/95609, U.S. patent application Ser. No. 08/004,554, filed Jan. 8,1998, entitled, "Polyimide and Doped Metal Oxide Fuser Components,"Attorney Docket Number D/95609Q2, U.S. patent application Ser. No.08/004,421, filed Jan. 8, 1998, entitled, "Haloelastomer and Doped MetalOxide Film Components," Attorney Docket Number D/95609Q3, U.S. patentapplication Ser. No. 08/004,385, filed Jan. 8, 1998, entitled,"Polyimide and Doped Metal Oxide Intermediate Transfer Components," andAttorney Docket Number D/95609Q4, U.S. patent application Ser. No.08/004,492, filed Jan. 8, 1998, entitled, "Polyurethane and Doped MetalOxide Film Components." The disclosures of these applications each ofwhich are hereby incorporated by reference in their entirety.

Attention is directed to copending application Attorney Docket NumberD/95609, U.S. patent application Ser. No. 08/004,554, filed Jan. 8,1998, entitled, "Polyimide and Doped Metal Oxide Fuser Components,"Attorney Docket Number D/95609Q2, U.S. patent application Ser. No.08/004,421, filed Jan. 8, 1998, entitled, "Haloelastomer and Doped MetalOxide Film Components," Attorney Docket Number D/95609Q3, U.S. patentapplication Ser. No. 08/004,385, filed Jan. 8, 1998, entitled,"Polyimide and Doped Metal Oxide Intermediate Transfer Components," andAttorney Docket Number D/95609Q4, U.S. patent application Ser. No.08/004,492, filed Jan. 8, 1998, entitled, "Polyurethane and Doped MetalOxide Film Components." The disclosures of these applications each ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates generally to an imaging apparatus andcompositions useful as layers for film components thereof, for use inelectrostatographic, including digital, apparatuses. The compositionsherein are useful for many purposes including layers for fixing films,bias transfer films, intermediate transfer films, transfix films, andthe like. More specifically, the present invention relates tocompositions comprising a haloelastomer and a doped metal oxideconductive filler in order to impart a desired resistivity wherein, inembodiments, the resistivity is stable to changes in the environment,such as changes in relative humidity and temperature. In specificembodiments, the doped metal oxide conductive filler is an antimonydoped tin oxide filler. The compositions of the present invention may beuseful in films used in xerographic machines, especially color machines.

In a typical electrostatographic reproducing apparatus, a light image ofan original to be copied is recorded in the form of an electrostaticlatent image upon a photosensitive member and the latent image issubsequently rendered visible by the application of electroscopicthermoplastic resin particles which are commonly referred to as toner.The visible toner image is then in a loose powdered form and can beeasily disturbed or destroyed. The toner image is usually fixed or fusedupon a support which may be the photosensitive member itself or othersupport sheet such as plain paper.

In many of the components useful in the xerographic process, it isdesirable to be able to tailor the resistivity of layers of componentsfor proper and efficient workability. In addition, it is desirable thatthe resistivity of the components remain relatively constant and thatthe resistivity not be sensitive to changes in the environment, such aschanges in temperature and/or relative humidity. Therefore, it isdesirable that the resistivity of layers useful in xerographiccomponents be controlled.

Attempts at controlling the conductivity of layers, especially outerlayers, of components, have been accomplished by, for example, addingconductive fillers such as ionic additives to the surface layer of thecomponents. However, to some extent, there are problems associated withthe use of these additives. In particular, undissolved particlesfrequently bloom or migrate to the surface of a polymer and cause animperfection in the polymer. This leads to a nonuniform resistivity,which in turn, leads to poor antistatic properties and poor mechanicalstrength for layers using the filled polymers. The ionic additives onsurface layers may interfere with toner release and affect toner offsetwhen the filled polymers are used as layers for intermediate transfermembers, fuser members, bias transfer members, transfix members, and thelike. The higher temperatures of the fusing process also increase themobility of the ionic components and increase depletion rates.Furthermore, bubbles appear in the conductive polymer, some of which canonly be seen with the aid of a microscope, others of which are largeenough to be observed with the naked eye. These bubbles provide the samekind of difficulty as the undissolved particles in the polymer namely,poor or nonuniform electrical properties and poor mechanical properties.

In addition, the ionic additives themselves are sensitive to changes intemperature, humidity, operating time and applied field. Thesesensitivities often limit the resistivity range. For example, theresistivity usually decreases by up to two orders of magnitude or moreas the humidity increases from 20% to 80% relative humidity. This effectlimits the operational or process latitude.

Moreover, ion transfer can also occur in these systems. The transfer ofions will lead to contamination problems, which in turn, can reduce thelife of the machine. Ion transfer also increases the resistivity of thepolymer member after repetitive use. This can limit the process andoperational latitude and eventually the ion-filled polymer componentwill be unusable.

Use of carbon black as a conductive filler has also been disclosed.Carbon black has been the chosen additive for imparting conductiveproperties in electrostatographic films. Carbon black is relativelyinexpensive and very efficient in that a relatively small percentage canimpart a high degree of conductivity. However, in practice with thismaterial, it difficult and sometimes impossible to fabricate productswith the desired level of conductivity. Further, films filled withcarbon black have a tendency to contaminate their surroundings withblack, conductive debris. In particular, the carbon black can causeundesirable black marks on the copied or printed substrates. Carbonblack particles can also impart other specific adverse effects. Suchcarbon dispersions are difficult to prepare due to carbon agglomeration,and the resulting layers may deform due to random hard carbonagglomerate formation sites as well as non-uniform electricalproperties. This can lead to an adverse change in the conformability ofthe layer.

Many doped metal oxides offer significant advantages in both color andtransparency when compared to carbon black. They are, however,relatively expensive and usually require higher dosages to achievecomparable levels of conductivity. In addition, dispersion of metaloxides can lead to short comings in surface roughness and particle size.

U.S. Pat. No. 5,147,751 discloses that a polyurethane with antimonydoped tin oxide filler may be used as the outer protective layer of aphotoreceptor. The patent also discloses that the outer layer may becomprised of a fluoroplastic binder resin.

U.S. Pat. No. 4,426,435 discloses an electrophotographic light-sensitivemember comprising a conductive support, a photoconductive layer and aprotective outer layer, wherein the protective outer layer may becomprised of a binder of, for example, fluorocarbon or polyurethane, anda filler, such as, for example, antimony doped tin oxide.

U.S. Pat. No. 5,503,955 discloses the use of antimony doped tin oxide inpolyurethane or polyimide as an adhesive in a photoreceptor.

U.S. Pat. No. 5,635,327 discloses a photoreceptor having a surface layercomprised of a dried and/or cured product under a reduced pressure of aninorganic or organic high molecular weight material and a conductivemetal oxide dispersed therein. The high molecular weight resin isdisclosed as, for example, fluororesin, polyurethane or polyimide, andthe conductive filler is disclosed as, for example, antimony doped tinoxide.

U.S. Pat. No. 5,585,905 discloses an intermediate toner transfer membercomprising a substrate and an outer layer comprised of a fluoropolymerpolymerized from a plurality of monomers, at least one monomer being anolefin having only carbon atoms and hydrogen atoms, and at least onemonomer being fluorinated. The outer layer may include conductiveparticles such as antimony doped tin oxide.

Therefore, a need remains for compositions useful as layers forxerographic members for use in electrostatographic machines, wherein thelayer possesses the desired resistivity without the drawbacks of lack oftransparency of the layer which may adversely affect its use in colorproducts, especially color imaging systems. Further, a need remains fora compositions useful in conductive films having conductive fillerswhich impart the desired resistivity without compromising surfaceroughness. Moreover, a need exists for compositions useful as layers inwhich the resistivity thereof is uniform and is relatively unaffected bychanges in environmental conditions such as changes in humidity,temperature, and the like.

SUMMARY OF THE INVENTION

The present invention provides, in embodiments, a composition comprisinga) a haloelastomer consisting essentially of monomers selected from thegroup consisting of halogenated monomers, polyorganosiloxane monomers,and mixtures thereof; and b) a doped metal oxide filler.

In addition, the present invention provides, in embodiments, acomposition comprising a) a haloelastomer consisting essentially ofhalogenated monomers, and b) a doped metal oxide, wherein said dopedmetal oxide is present in an amount of from about 20 to about 30 percentby weight of total solids, and wherein said composition has a surfaceresistivity of from about 10⁶ to about 10¹³ ohms/sq.

BRIEF DESCRIPTION OF THE DRAWINGS

The above embodiments of the present invention will become apparent asthe following description proceeds upon reference to the drawings whichinclude the following figures:

FIG. 1 is an illustration of a general electrostatographic apparatus.

FIG. 2 is a sectional view of an embodiment of the present invention,wherein the composition is formed into a film.

FIG. 3 is a graph of surface resistivity (100V ohm/sq 10E) versus amountof antimony doped tin oxide (parts per 100 parts fluoropolymer).

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to compositions useful as layers forcomponents, and in particular, film components including films, sheets,belts and the like. In one embodiment of the present invention, thecomposition comprises a haloelastomer and electrically conductivefillers. In another embodiment, the composition comprises ahaloelastomer having electrically conductive fillers dispersed orcontained therein. In a preferred embodiment, the fillers are dopedmetal oxide fillers, and in a particularly preferred embodiment, thefillers are antimony doped tin oxide fillers.

Referring to FIG. 1, in a typical electrostatographic reproducingapparatus, a light image of an original to be copied is recorded in theform of an electrostatic latent image upon a photosensitive member andthe latent image is subsequently rendered visible by the application ofelectroscopic thermoplastic resin particles which are commonly referredto as toner. Specifically, photoreceptor 10 is charged on its surface bymeans of a charger 12 to which a voltage has been supplied from powersupply 11. The photoreceptor is then imagewise exposed to light from anoptical system or an image input apparatus 13, such as a laser and lightemitting diode, to form an electrostatic latent image thereon.Generally, the electrostatic latent image is developed by bringing adeveloper mixture from developer station 14 into contact therewith.Development can be effected by use of a magnetic brush, powder cloud, orother known development process. A dry developer mixture usuallycomprises carrier granules having toner particles adheringtriboelectrically thereto. Toner particles are attracted from thecarrier granules to the latent image forming a toner powder imagethereon. Alternatively, a liquid developer material may be employed,which includes a liquid carrier having toner particles dispersedtherein. The liquid developer material is advanced into contact with theelectrostatic latent image and the toner particles are deposited thereonin image configuration.

After the toner particles have been deposited on the photoconductivesurface, in image configuration, they are transferred to a copy sheet 16by transfer means 15, which can be pressure transfer or electrostatictransfer. Alternatively, the developed image can be transferred to anintermediate transfer member and subsequently transferred to a copysheet. The transfer process can optionally include heating sufficient toachieve partial or full melting of the toner particles prior to or inthe transfer zones to, for example, create adhesive assist during thetransfer steps or even to achieve partial or else complete image fixingto the copy sheet.

After the transfer of the developed image is completed, copy sheet 16advances to fusing station 19, depicted in FIG. 1 as fusing and pressurerolls, wherein the developed image is fused to copy sheet 16 by passingcopy sheet 16 between the fusing and pressure members, thereby forming apermanent image. If complete fusing is accomplished during the transferstep, a post fusing station may not be required. Photoreceptor 10,subsequent to transfer, advances to cleaning station 17, wherein anytoner left on photoreceptor 10 is cleaned therefrom by use of a blade(as shown in FIG. 1), brush, or other cleaning.

The compositions herein may be useful as layers of xerographiccomponents. The compositions comprise a haloelastomer and a filler,preferably a doped metal oxide filler. Preferred haloelastomers includehaloelastomers comprising halogen monomers, halolastomers comprisingpolyorganosiloxanes, and haloelastomers comprising halogen monomers andpolyorganosiloxane monomers. A particularly preferred haloelastomercomprises only halogenated monomers.

Examples of haloelastomers comprising halogen monomers includefluoroelastomers comprising copolymers and terpolymers ofvinylidenefluoride, hexafluoropropylene and tetrafluoroethylene, whichare known commercially under various designations as VITON A®, VITON E®,VITON E60C®, VITON E45®, VITON E430®, VITON B 910®, VITON GH®, VITONB50®, VITON E45®, and VITON GF®. The VITON® designation is a Trademarkof E. I. DuPont de Nemours, Inc. Two preferred known fluoroelastomersare (1) a class of copolymers of vinylidenefluoride, hexafluoropropyleneand tetrafluoroethylene, known commercially as VITON A®, (2) a class ofterpolymers of vinylidenefluoride, hexafluoropropylene andtetrafluoroethylene known commercially as VITON B®, and (3) a class oftetrapolymers of vinylidenefluoroide, hexafluoropropylene,tetrafluoroethylene and a cure site monomer. VITON A®, and VITON B®, andother VITON® designations are trademarks of E. I. DuPont de Nemours andCompany.

In another preferred embodiment, the fluoroelastomer is a tetrapolymerhaving a relatively low quantity of vinylidenefluoride. An example isVITON GF®, available from E. I. DuPont de Nemours, Inc. The VITON GF®has 35 mole percent of vinylidenefluoride, 34 mole percent ofhexafluoropropylene and 29 mole percent of tetrafluoroethylene with 2percent cure site monomer. The cure site monomer can be those availablefrom DuPont such as 4-bromoperfluorobutene-1,1,1-dihydro-4-bromoperfluorobutene-1, 3-bromoperfluoropropene-1,1,1-dihydro-3-bromoperfluoropropene-1, or any other suitable, known,commercially available cure site monomer.

Other preferred haloelastomers include haloelastomers comprisingpolyorganosiloxane monomers and haloelastomers comprising halogenmonomers and polyorganosiloxane monomers, such as polymer compositesincluding, for example, volume grafted elastomers, titamers, graftedtitamers, ceramers, and grafted ceramers.

In one embodiment of the invention, the haloelastomer is a volumegrafted elastomer. Volume grafted elastomers are a special form ofhydrofluoroelastomer and are substantially uniform integralinterpenetrating networks of a hybrid composition of a fluoroelastomerand a polyorganosiloxane, the volume graft having been formed bydehydrofluorination of fluoroelastomer by a nucleophilicdehydrofluorinating agent, followed by addition polymerization by theaddition of an alkene or alkyne functionally terminatedpolyorganosiloxane and a polymerization initiator.

Volume graft, in embodiments, refers to a substantially uniform integralinterpenetrating network of a hybrid composition, wherein both thestructure and the composition of the fluoroelastomer andpolyorganosiloxane are substantially uniform when taken throughdifferent slices of the layer. A volume grafted elastomer is a hybridcomposition of fluoroelastomer and polyorganosiloxane formed bydehydrofluorination of fluoroelastomer by nucleophilicdehydrofluorinating agent followed by addition polymerization by theaddition of alkene or alkyne functionally terminated polyorganosiloxane.Examples of specific volume graft elastomers are disclosed in U.S. Pat.No. 5,166,031; U.S. Pat. No. 5,281,506; U.S. Pat. No. 5,366,772; andU.S. Pat. No. 5,370,931, the disclosures of which are hereinincorporated by reference in their entirety.

In embodiments, the polyorganosiloxane has the formula I: ##STR1## whereR is an alkyl from about 1 to about 24 carbons, or an alkenyl of fromabout 2 to about 24 carbons, or a substituted or unsubstituted aryl offrom about 4 to about 24 carbons; A is an aryl of from about 6 to about24 carbons, a substituted or unsubstituted alkene of from about 2 toabout 8 carbons, or a substituted or unsubstituted alkyne of from about2 to about 8 carbons; and n is from about 2 to about 400, and preferablyfrom about 10 to about 200 in embodiments.

In preferred embodiments, R is an alkyl, alkenyl or aryl, wherein thealkyl has from about 1 to about 24 carbons, preferably from about 1 toabout 12 carbons; the alkenyl has from about 2 to about 24 carbons,preferably from about 2 to about 12 carbons; and the aryl has from about4 to about 24 carbon atoms, preferably from about 6 to about 18 carbons.R may be a substituted aryl group, wherein the aryl may be substitutedwith an amino, hydroxy, mercapto or substituted with an alkyl having forexample from about 1 to about 24 carbons and preferably from 1 to about12 carbons, or substituted with an alkenyl having for example from about2 to about 24 carbons and preferably from about 2 to about 12 carbons.In a preferred embodiment, R is independently selected from methyl,ethyl, and phenyl. The functional group A can be an alkene or alkynegroup having from about 2 to about 8 carbon atoms, preferably from about2 to about 4 carbons, optionally substituted with an alkyl having forexample from about 1 to about 12 carbons, and preferably from about 1 toabout 12 carbons, or an aryl group having for example from about 6 toabout 24 carbons, and preferably from about 6 to about 18 carbons.Functional group A can also be mono-, di-, or trialkoxysilane havingfrom about 1 to about 10 and preferably from about 1 to about 6 carbonsin each alkoxy group, hydroxy, or halogen. Preferred alkoxy groupsinclude methoxy, ethoxy, and the like. Preferred halogens includechlorine, bromine and fluorine. A may also be an alkyne of from about 2to about 8 carbons, optionally substituted with an alkyl of from about 1to about 24 carbons or aryl of from about 6 to about 24 carbons. Thegroup n is from about 2 to about 400, and in embodiments from about 2 toabout 350, and preferably from about 5 to about 100. Furthermore, in apreferred embodiment n is from about 60 to about 80 to provide asufficient number of reactive groups to graft onto the fluoroelastorner.In the above formula, typical R groups include methyl, ethyl, propyl,octyl, vinyl, allylic crotnyl, phenyl, naphthyl and phenanthryl, andtypical substituted aryl groups are substituted in the ortho, meta andpara positions with lower alkyl groups having from about 1 to about 15carbon atoms. Typical alkene and alkenyl functional groups includevinyl, acrylic, crotonic and acetenyl which may typically be substitutedwith methyl, propyl, butyl, benzyl, tolyl groups, and the like.

Ceramers are also preferred polymer composites useful as xerographiccoatings. A ceramer generically refers to a hybrid material of organicand composite composition which typically has ceramic-like properties.As used herein, the term ceramer refers to, in embodiments, a compositepolymer comprised of substantially uniform integral interpenetratingnetworks of a haloelastomer and silicon oxide (tetraethoxyorthosilicate). The term grafted ceramer refers to, in embodiments, acomposite polymer comprised of substantially uniform integralinterpenetrating networks of a polyorganosiloxane grafted haloelastomerand silicon oxide network. In the grafted ceramer, the haloelastomer isthe first monomer segment, the polyorganosiloxane is the third monomersegment and the second monomer segment is tetraethoxy orthosilicate, theintermediate to a silicon oxide network. Both the structure and thecomposition of the polyorganosiloxane grafted haloelastomer and siliconoxide networks are substantially uniform when viewed through differentslices of the layer. The phrase interpenetrating network refers to theintertwining of the haloelastomer and silicon oxide network polymerstrands for the ceramer, and to the intertwining of thepolyorganosiloxane grafted haloelastomer and silicon oxide polymernetwork strands for the grafted ceramer. The phrase haloelastomer may beany suitable halogen containing elastomer such as a chloroelastomer, abromoelastomer, or the like, mixtures thereof, and preferably is afluoroelastomer. Examples of suitable fluoroelastomers are set forthabove. Examples of suitable polyorganosiloxanes are referred to above.The phrases "silicon oxide," "silicon oxide network," "network ofsilicon oxide" and the like refer to alternating, covalently bound atomsof metal and oxygen, wherein alternating atoms of silicon and oxygen mayexist in a linear, branched, and/or lattice pattern. The atoms ofsilicon and oxygen exist in a network and not as discrete particles.Preferred ceramers and grafted ceramers are described in U.S. Pat. No.5,337,129, the disclosure of which is hereby incorporated by referencein its entirety.

In a preferred embodiment of the invention, the ceramer has thefollowing formula II: ##STR2##

In the above formula, the symbol "˜" represents a continuation of thepolymer network.

In a preferred embodiment of the invention, a grafted ceramer has thefollowing formula III: ##STR3##

In the above formula, R is the R group of the polyorganosiloxanedescribed above and may be a substituent as defined herein for the Rgroup of the polyorganosiloxane; n is a number as herein defined for then of the polyorganosiloxane above; and the symbol "˜" represents acontinuation of the polymer network.

Titamers are also preferred polymer composites suitable for thexerographic coating herein. Titamers are discussed in U.S. Pat. Nos.5,500,298; 5,500,299; and 5,486,987, the disclosures each of which arehereby incorporated by reference in their entireties. As used herein,the phrase titamer refers to a composite material comprised ofsubstantially uniform integral interpenetrating networks ofhaloelastomer and titanium oxide network, wherein both the structure andthe composition of the haloelastomer and titanium oxide network, aresubstantially uniform when viewed through different slices of thecoating layer. The phrase grafted titamer refers to a substantiallyuniform integral interpenetrating networks of a polyorganosiloxanegrafted haloelastomer and titanium oxide network, wherein thehaloelastomer is the first monomer segment, the polyorganosiloxane isthe third grafted monomer segment and titanium isobutoxide, theintermediate to titanium oxide network, is the second monomer segment.Both the structure and the composition of the polyorganosiloxane graftedhaloelastomer and titanium oxide network are substantially uniform whenviewed through different slices of the xerographic coating layer. Thephrase interpenetrating network refers to the intertwining of thehaloelastomer and titanium oxide network polymer strands for thetitamer, and to the intertwining of the polyorganosiloxane graftedhaloelastomer and titanium oxide network polymer strands for the graftedtitamer. The phrase haloelastomer may be any suitable halogen containingelastomer such as a chloroelastomer, a bromoelastomer, or the like,mixtures thereof, and preferably is a fluoroelastomer as describedabove. The phrase "titanium oxide," network of titanium oxide," or"titanium oxide network" or similar phrases refers to alternating,covalently bound atoms of titanium and oxygen, wherein the alternatingatoms of titanium and oxygen may exist in a linear, branched and/orlattice pattern. The atom of titanium and oxygen exist in a network andnot as discrete particles.

Examples of titamers include those having the following formula IV:##STR4##

In the above formula, the symbol "˜" represents the continuation of thepolymeric network.

Examples of grafted titamers include those having the following formulaV: ##STR5##

In the above formula, R is the R group of the polyorganosiloxanedescribed above and may be a substituent as defined herein for the Rgroup of the polyorganosiloxane; n is a number as herein defined for then of the polyorganosiloxane above; and the symbol "˜" represents acontinuation of the polymer network.

Other preferred haloelastomers include fluoroelastomers such asfluorosilicones, fluorourethanes, fluoroacrylate such as LUMIFLON®available from ICI Americas, Inc., Wilmington, Del., and otherfluoroelastomers such as polyvinyl fluoride such as TEDLAR®,polyvinylidiene fluoride such as KYNAR®, and the like.

In addition, preferred haloelastomers include those comprisingpolyorganosiloxane copolymers such as polyamide polyorganosiloxanecopolymers, polyimide polyorganosiloxane copolymers, polyesterpolyorganosiloxane copolymers, polysulfone polyorganosiloxanecopolymers, polystyrene polyorganosiloxane copolymers, polypropylenepolyorganosiloxane copolymers, and polyester polyorganosiloxanecopolymers.

The haloelastomer is present in the composition in an amount of fromabout 95 to about 35 percent, preferably from about 90 to about 50percent, and particularly preferred is from about 80 to about 70 percentby weight of total solids. Total solids as used herein refers to thetotal amount by weight of haloelastomer, doped metal oxide filler, andany additional additives, fillers or like solid materials.

The compositions comprise electrically conductive particles dispersedtherein. These electrical conductive particles decrease the materialresistivity into the desired resistivity range. The desired surfaceresistivity is from about 10⁶ to about 10¹³, preferably from about 10⁸to about 10¹², and more preferably from about 10¹⁰ to about 10¹²ohms/sq. The preferred volume resistivity range is from about 10⁵ toabout 10¹⁴, preferably from about 10⁸ to about 10¹⁴, and particularlypreferred is from about 10¹² to about 10¹⁴ ohm-cm. The desiredresistivity can be provided by varying the concentration of theconductive filler. It is important to have the resistivity within thisdesired range. When the compositions are formed into film components,the components may exhibit undesirable effects if the resistivity is notwithin the required range. Other problems include resistivity that issusceptible to changes in temperature, relative humidity, and the like.The combination of haloelastomer and doped metal oxide filler, inembodiments, allows for tailoring of a desired resistivity, and further,allows for a stable resistivity virtually unaffected by changes inrelative humidity and temperature.

Examples of conductive fillers include doped metal oxides such asaluminum doped zinc oxide (ZnO), antimony doped titanium dioxide (TiO₃),metal oxides such as barium titanate (BaTiO₃), titanium oxide, and thelike, including organic complexes such as polypyrrole, polyanaline, andthe like. In a preferred embodiment of the invention, the electricallyconductive filler is antimony doped tin oxide. Suitable antimony dopedtin oxides include those antimony doped tin oxides coated on an inertcore particle (e.g., ZELEC® ECP-S, M and T, available from DuPontChemicals Jackson Laboratories, Deepwater, N.J.) and those antimonydoped tin oxides without a core particle (e.g., ZELEC® ECP-3005-XC andZELEC® ECP-3010-XC). The core particle may be mica, TiO₂ or acicularparticles having a hollow or a solid core.

In a preferred embodiment, the antimony doped tin oxides are prepared bydensely layering a thin layer of antimony doped tin oxide onto thesurface of a silica shell or silica-based particle, wherein the shell,in turn, has been deposited onto a core particle. The crystallites ofthe conductor are dispersed in such a fashion so as to form a denseconductive surface on the silica layer. This provides optimalconductivity. Also, the outer particles are fine enough in size toprovide adequate transparency. The silica may either be a hollow shellor layered on the surface of an inert core, forming a solid structure.

Preferred forms of antimony doped tin oxide are commercially availableunder the tradename ZELEC® ECP (electroconductive powders) from DuPont.Particularly preferred antimony doped tin oxides are ZELEC® ECP 1610-S,ZELEC® ECP 2610-S, ZELEC® ECP 3610-S, ZELEC® ECP 1703-S, ZELEC® ECP2703-S, ZELEC® ECP 141 0-M, ZELEC® ECP 3005-XC, ZELEC® ECP 3010-XC,ZELEC® ECP 1410-T, ZELEC® ECP 3410-T, ZELEC® ECP-S-X1, and the like.Three commercial grades of ZELEC® ECP powders are preferred and includean acicular, hollow shell product (ZELEC® ECP-S), an equiaxial titaniumdioxide core product (ZELEC ECP-T), and a plate shaped mica core product(ZELEC® ECP-M). The following Tables demonstrate the product propertiesof ZELEC® ECP. This information was taken from a DuPont ChemicalsJackson Laboratory product brochure, dated September, 1992 and entitled,"The Application of Zelec ECP in Static Dissipative

                  TABLE 1    ______________________________________    Product Physical Properties (S, T & M)    Property   Core      Shape      Mean Part. Size    ______________________________________    ECP-S      Hollow    Acicular   3 microns    ECP-T      Solid     Equiaxial  1 micron    ECP-M      Solid     Platelike  10 microns    ______________________________________

                  TABLE 2    ______________________________________    Product Chemical Properties (S, T & M)    Property   ECP-S      ECP-T      ECP-M    ______________________________________    Bulk Density               0.4 gm/cc  1.0 gm/cc  0.6 gm/cc    Specific gravity               3.9 gm/cc  4.9 gm/cc  3.9 gm/cc    Surface area               50 m.sup.2 /gm                          20 m.sup.2 /gm                                     30 m.sup.2 /gm    Mean part. size               3 microns  1 micron   10 micron    Dry powder resist               2-30 ohm-cm                          2-30 ohm-cm                                     20-300 ohm-cm    Core       Hollow     TiO.sub.2  Mica    ______________________________________

                  TABLE 3    ______________________________________    Product Properties (XC)    Property      3005-XC      3010-XC    ______________________________________    Antimony %    6.5          10    Bulk powder resist.                  .5 to 3 ohm-cm                               .5 to 3 ohm-cm    Specific gravity                  6.5 to 7.5 gm/cc                               6.5 to 7.5 gm/cc    Surface area  15 to 30 m.sup.2 /gm                               60 to 80 m.sup.2 /gm    Particle size (D50)                  .7 microns   2 microns    ______________________________________

The preferred particle size of the doped metal oxide is from about 0.5to about 15 microns, and preferably from about 1 to about 10 microns.

In a particularly preferred embodiment of the invention, antimony dopedtin oxide is added to the haloelastomer in an amount of about 5 to about65 percent by weight of total solids, preferably from about 10 to about50 percent by weight of total solids, and particularly preferred of fromabout 20 to about 30 percent by weight of total solids. Total solids isdefined as the amount of haloelastomer, filler(s), any additives, andany other solid material additives of fillers.

Additives may be present in the composition. The type of additive willdepend, in part, on what type of xerographic component the compositionsare used in. Additives most likely to be used in xerographic componentlayers include cross linkers, silanes, titanates, zirconates, colorants,extenders, and the like. In addition, additional fillers may bedispersed in the haloelastomer. Examples of suitable fillers includecarbon black, graphite, boron nitride, and metal oxides such as ironoxide, magnesium oxide, aluminum oxide, copper oxide, tin oxide,titanium oxide, zinc oxide, chrome oxide, nickel oxide, and the like,and mixtures thereof. The additional filler may be present in an amountof from about 1 to about 40 and preferably from about 4 to about 20parts by weight of total solids.

FIG. 2 depicts an embodiment of the invention, wherein the compositionis formed into a film layer 24. Film layer 24 comprises a haloelastomersubstrate 30 with antimony doped tin oxide fillers 31 dispersed therein.

The compositions of the present invention can be formed into variousxerographic component layers, and in preferred embodiments, can beformed into film components of any suitable configuration. Examples ofsuitable configurations include a sheet, a film, a web, a foil, a strip,a coil, a cylinder, a drum, an endless strip, a circular disc, a beltincluding an endless belt, an endless seamed flexible belt, an endlessseamless flexible belt, an endless belt having a puzzle cut seam, andthe like. It is preferred that the substrate comprising the compositionbe an endless seamed flexible belt or seamed flexible belt, which may ormay not include puzzle cut seams. Examples of such belts are describedin U.S. Pat. Nos. 5,487,707; 5,514,436; and U.S. patent application Ser.No. 08/297,203 filed Aug. 29, 1994, the disclosures each of which areincorporated herein by reference in their entirety. A method formanufacturing reinforced seamless belts is set forth in U.S. Pat. No.5,409,557, the disclosure of which is hereby incorporated by referencein its entirety.

The compositions herein may be formed into films, preferably in the formof a belt, has a width, for example, of from about 150 to about 2,000mm, preferably from about 250 to about 1,400 mm, and particularlypreferred is from about 300 to about 500 mm. The circumference of thebelt is preferably from about 75 to about 2,500 mm, more preferably fromabout 125 to about 2,100 mm, and particularly preferred from about 155to about 550 mm.

Compositions comprising a haloelastomer and a doped metal oxide, inembodiments, allow for layers to be formed wherein the resistivity ofthe layers can be tailored to a desired resistivity which is relativelyunaffected by changes in environmental conditions such as, for example,temperature and relative humidity. The compositions further provide for,in embodiments, layers which allow for tailoring of a desiredresistivity without the drawbacks of lack of transparency and withoutcompromising surface roughness.

Specific embodiments of the invention will now be described in detail.These examples are intended to be illustrative, and the invention is notlimited to the materials, conditions, or process parameters set forth inthese embodiments. All parts are percentages by weight of total solidsas defined above unless otherwise indicated.

EXAMPLES

Example 1

Fluoroelastomer filled with antimony doped tin oxide

An amount of 100 parts by weight fluoroelastomer (VITON B50®) was mixedwith 512 parts by weight methyl ethyl ketone (MEK). Fillers were thenadded to the above fluoroelastomer solution in an 8 ounce glass jar asfollows: 1 part by weight Ca(OH)₂, 2 parts by weight MgO, and variousamounts of antimony doped tin oxide (20, 25, 30 and 40 parts by weight,respectively, antimony doped tin oxide sold under the tradename ZELEC®EPC 3005-XC available from DuPont Chemicals Jackson Laboratories,Deepwater, N.J.). Stainless steel shots (1/8 inches in diameter) wereadded in an amount of 150 grams to the above mixture of fluoroelastomerin solution with added fillers. The resulting compound was mixed on apaint shaker for 25 minutes and then filtered through a regular screenpaint filter. Coatings were made with the four different levels ofantimony doped tin oxide fillers using vacuum platen and manual drawdown techniques. The coatings were then air dried for about 17 hours andthen post cured, using a step heat cure, for approximately 24 hours.

The coatings were then measured for resistivity. The coatingsprogressively became more conductive as the amount of antimony doped tinoxide filler increased. Specifically, the resistivity decreased fromabout 10¹⁴ ohm-cm to about 10¹² ohm-cm. This is shown in FIG. 3 attachedherewith which is a graph showing surface resistivity (100V ohm/sq 10E)versus amount of antimony doped tin oxide (parts per 100 partsfluoropolymer).

In addition, it was determined that the electronic conduction andresistivity was less effected by changes in percent relative humidityand temperature than ionic conduction. Therefore it is anticipated thatthe above material will be stable to environmental conditions.

While the invention has been described in detail with reference tospecific and preferred embodiments, it will be appreciated that variousmodifications and variations will be apparent to the artisan. All suchmodifications and embodiments as may readily occur to one skilled in theart are intended to be within the scope of the appended claims.

We claim:
 1. A composition comprising a haloelestomer selected from thegroup consisting of a) copolymers of vinylidenefluoride,hexafluoropropylene, and tetrafluoroethylene, b) terpolymers ofvinylidenefluoride, hexafluoropropylene and tetrafluoroethylene, and c)tetrapolymers of vinylidenefluoride, hexafluoropropylene,tetrafluoroetheylene, and a cure site monomer; and a doped metal oxidefiller.
 2. The composition claim 1, wherein said doped metal oxide is anantimony doped tin oxide filler.
 3. The composition of claim 1, whereinsaid composition has a volume resistivity of from about 10⁵ to about10¹⁴ ohm-cm.
 4. The composition of claim 1, wherein said composition hasa surface resistivity of from about 10⁶ to about 10¹³ ohm/sq.
 5. Thecomposition of claim 1, wherein said haloelastomer consists essentiallyof 35 mole percent of vinylidenefluoride, 34 mole percent ofhexafluoropropylene, 29 mole percent of tetrafluoroethylene, and 2percent cure site monomer.
 6. The composition of claim 1, wherein saidhaloelastomer consists essentially of polyorganosiloxane monomers andhalogenated monomers.
 7. The composition of claim 6, wherein saidhaloelastomer is selected from the group consisting of volume graftedfluoroelastomers, ceramers, grafted ceramers, titamers and graftedtitamers.
 8. The composition of claim 6, wherein said haloelastomercomprises an additional monomer capable of reacting with saidpolyorganosiloxane monomer to form a polyorganosiloxane copolymer. 9.The composition of claim 8, wherein said polyorganosiloxane copolymer isselected from the group consisting of polyamide polyorganosiloxanecopolymers, polyimide polyorganosiloxane copolymers, polyesterpolyorganosiloxane copolymers, polysulfone polyorganosiloxanecopolymers, polystyrene polyorganosiloxane copolymers, polypropylenepolyorganosiloxane copolymers, and polyester polyorganosiloxanecopolymers.
 10. The composition of claim 1, wherein said doped metaloxide filler is present in an amount of from about 5 to about 65 percentby weight of total solids.
 11. The composition of claim 10, wherein saiddoped metal oxide filler is present in an amount of from about 20 toabout 30 percent by weight of total solids.
 12. The composition of claim1, wherein said haloelastomer is present in an amount of from about 95to about 35 percent by weight of total solids.
 13. The composition ofclaim 11, wherein said haloelastomer is present in an amount of fromabout 80 to about 70 percent by weight of total solids.
 14. Thecomposition of claim 1, further comprising a conductive filler selectedfrom the group consisting of carbon black, graphite, boron nitride, ironoxide, copper oxide, magnesium oxide, aluminum oxide, tin oxide,titanium oxide, zinc oxide, chrome oxide, nickel oxide, and mixturesthereof.
 15. The composition of claim 2, wherein said antimony doped tinoxide comprises an inert core particle.
 16. The composition of claim 15,wherein said core particle is selected from the group consisting ofmica, tin oxide, and an acicular particle.
 17. The composition of claim16, wherein said acicular particle is hollow or solid.
 18. Thecomposition of claim 1, wherein said doped metal oxide has a particlesize of from about 1 to about 10 microns.
 19. A composition comprising ahaloelastomer selected from the group consisting of a) copolymers ofvinylidenefluoride, hexafluoropropylene, and tetrafluoroethylene, b)terpolymers of vinylidenefluoride, hexafluoropropylene andtetrafluoroethylene, and c) tetrapolymers of vinylidenefluoride,hexafluoropropylene, tetrafluoroethylene, and a cure site monomer; and adoped metal oxide, wherein said doped metal oxide is present in anamount of from about 20 to about 30 percent by weight of total solids,and wherein said composition has a surface resistivity of from about 10⁶to about 10¹³ ohms/sq.